Dispensing of sticky and/or viscous materials from a syringe requires the application of a significant force to the plunger of the syringe. Depending on the viscosity of the dispensed material and the amount of this material, the user may experience difficulties in generating and/or maintaining the necessary force for a required period of time. Consequently, inadequate force and/or fatigue, particularly when a need arises to use a syringe repetitively, can lead to undesirable, inaccurate results.
Conventional devices that amplify an input force typically are configured with a pistol-type handle having an attached lever which amplifies the force of the person's hand and applies it to the plunger of a syringe.
Regular syringes, those that do not have a force-amplification structure, are typically held by the user between the index and middle fingers whereas the thumb applies the force to the syringe plunger. When significant force is not required, such a syringe is associated with accurate aiming of the substance to be dispensed and full control of the dispensing, since the motion of the thumb coincides with the line of the plunger's movement.
During the use of a conventional force amplifying syringe, the line of movement of the plunger is located above the user's hand, and the distribution of substance from the syringe occurs when the user squeezes the lever of the syringe. This configuration does not allow accurate aiming of the substance and hampers dispensing, especially in applications where such substance delivery occurs in tight areas with limited visibility. These conditions can be encountered in numerous industries including, but not limited to, medical procedures, such bonding fractured bones or cementing ruptured spinal disks.
It is, therefore, desirable to provide a force amplifier configured to provide accurate dispensing of substance while not requiring the application of significant axial loads.